Various types of guides have been devised for aiding in launching boats from and loading boats onto boat trailers. Such guides may be divided into two general classes, resilient and non-resilient guides.
Non-resilient guides serve generally only as markers for indicating the location of a submerged or partially submerged trailer and act as rigid pilings to stop sidewise movement of the boat during launching or loading thereof. Since the hull is normally narrower near the stern that at other portions, unless special provision is made for moving non-resilient guides toward and away from each other, the guides must be spaced apart far enough for the widest part of the hull to move therebetween during loading and unloading.
Resilient guides overcome these difficulties by flexing toward or away from each other but are normally relatively expensive and subject to wear because of inter-engaging parts which move against each other and are subject to jamming of the parts by sticks, seaweed, and the like. For example, coil or spiral springs are prone to snagging seaweed, and the like, and a stick may become jammed as a pivot assembly closes. Furthermore, relatively moving parts generally require lubrication which is generally overlooked since the owner is considerably more interested in the boat than in the trailer. Another charactieristic of resilient type guides is that they are provided with rollers, or the like, which protrude and are likely to snag on part of the hull, such as spray rails, for example. Such snagging is particularly likely to occur if the hull lists during launching or loading, as when a person sits on the gunnel of a small boat, or in heavy weather when the hull lists from side to side.
The following United States patents show various forms of both resilient and non-resilient guides of the previously discussed types: U.S. Pat. Nos. 2,636,745; 3,021,969; 3,031,093; 3,160,297; 3,178,043; 3,447,815; 3,455,472; 3,603,465; 3,632,138; 3,873,130; 3,885,146; 3,887,093; and 4,010,962.